1. Field of the Invention
The present invention relates, generally, to stabilizing devices for recreational vehicles and more particularly to a better undercarriage frame into which a stabilizer jack is integrated.
2. Description of the Prior Art
Recreational vehicles have spring suspension systems to make the ride smooth for both fixtures and passengers. While the suspension system improves comfort of passengers and minimizes vibrating of fixtures within the vehicle, it allows instability and unwanted rocking motions when passengers move about therein while the vehicle is parked. Suspension systems and supporting wheels allow for the vehicle to rock both fore and aft and laterally on the springs as well as fore and aft with the wheels as such wheels roll slightly fore and aft in response to shifting weight.
The recreational vehicle industry has developed several stabilizer jacks in an attempt to solve the problem of recreational vehicle and trailer rocking. By way of example, several devices can be found in U.S. Pat. Nos. 3,096,065; 3,475,008; 3,656,778; 3,826,470; 3,854,750; 3,870,276; 4,103,869; 5,042,779; and 5,205,586. Conceptually, the most desirable devices provide maximum stability with a minimum number of parts. Such a design reduces costs and helps maximize weight efficiency ratios.
U.S. Pat. No. 5,205,586 to Tallman, assigned to the assignee of the present application shows a recreational vehicle stabilizer, including jack assemblies mounted at the laterally opposite extremities of telescopical jack housing channels so that the housing can be easily adjusted to different width trailers. Such devices, while enjoying a degree of commercial success, suffer the shortcoming that they require a separate housing of sufficient rigidity and strength to carry the jack assemblies and to transmit the jack forces to the vehicle frame without undue rocking or play. Even then, it is recognized that the stabilizing forces being directed through the jack housings to the vehicle frames allow for some degree of flex and play in the connections of such housings and consequent racking of the housings as weight is applied thereto from the interior of the trailer. Additionally, shifting of weight fore and aft within the recreational vehicle which tends to rock the supporting wheels fore and aft only resisted to a minor extent. Thus, to properly stabilize the vehicle it is necessary to provide auxiliary stabilization against backward and forward rocking of the support wheels, as by application of a wheel block or choke.
The strength of the jack assembly could be enhanced if the load of the jack assembly were born directly by the frame. This would ensure that the weight of the vehicle was supported by the strongest part of the vehicle. Furthermore, mounting of the stabilizer jacks to the outer perimeter of the RV floor, would provide the broadest and hence most stable support for the R.V. or trailer.
Since the frame members are typically disposed well underneath and away from the perimeter of the vehicle, jack assemblies of the prior art could not be placed both under the frame member and at the outer extremities of the vehicles without sacrificing strength, stability, durability and/or efficiency of weight and cost.
The rocking and vibrational motion of the vehicle in all directions is another problem associated with stabilizing recreational vehicles. Many prior art stabilizers are affixed under the vehicle oriented to extend in a direction perpendicular to the longitudinal frame members. The jack legs are thus usually lowered in rectilinear fashion in a traverse plane so that any bracing effect which might resist horizontal movement of the vehicle applies only to the transverse and not the longitudinal direction. Consequently, such devices are generally ineffective to effectively resist horizontal forward or rearward travelation of the body of the vehicle thus necessitating the use of additional accessories, such as wheel chokes to prevent rolling of the wheels.
Prior art jack stabilizer assemblies are generally constructed to be affixed to the frame after the vehicle is assembled. The points of affixation are often structurally weaker than the frame itself. Loads applied as a result of variable and unstabilizing loads over time subjects the jack systems to a weakening, loosening, breaking or buckling at said point of affixation.